decinfo

Syntax

decinfo(lmisys)
decX = decinfo(lmisys,X)

Description

The function decinfo
expresses the entries of a matrix variable X in
terms of the decision variables x1,
. . ., xN. Recall that the
decision variables are the free scalar variables of the problem, or
equivalently, the free entries of all matrix variables described in lmisys.
Each entry of X is either a hard zero, some decision
variable xn, or its opposite
–xn.

returns an integer matrix decX of the same
dimensions as X whose (i, j)
entry is

0 if X(i, j)
is a hard zero

n if X(i,
j) = xn (the n-th
decision variable)

–n if X(i,
j) = –xn

decX clarifies the structure
of X as well as its entry-wise dependence on x1,
. . ., xN. This is useful
to specify matrix variables with atypical structures (see lmivar).

decinfo can also be used
in interactive mode by invoking it with a single argument. It then
prompts the user for a matrix variable and displays in return the
decision variable content of this variable.